In the event of panel dead scenario, it is possible to receive a
mode set call before the panel has recovered. When this happens,
display should select watchdog TE as the vsync source.
Similarly when detecting a write pointer timeout, if the panel is
dead then watchdog TE should be or has already been configured and
display should not make a change to this vsync selection.
Change-Id: I732c75e54d734b00889151b914b0749ae1f27d08
Signed-off-by: Samantha Tran <samtran@codeaurora.org>